Isalo National Park is a National Park in the Toliara Province of Madagascar. The park is known for its wide variety of terrain, including sandstone formations, deep canyons, palm-lined oases, and grassland. The closest town is Ranohira, and the closest city is Toliara. A local guide is required for visitors entering the park, and guides and porters can be hired in Ranohira. Treks in the park can last from several hours to a week or longer. The main threat to this park comes from illegal wildfires set in the park. The wildfires limit the extent of forest and maximize grasslands used by cattle.